How difficult could be for me to get a green card?

You have not provided any information that you are eligible for a green card. To obtain a green card, you need to be the beneficiary of an approved immigrant visa petition. An immigrant visa petition is typically filed by a family member or employer. Assuming you have not maintained nonimmigrant status through your entire stay and may have accrued sufficient unlawful presence to trigger a bar to admission, you would only be able to receive a green card through marriage to a United Stares citizen while remaining in the country. Other avenues would require you to depart the United States and may also require a waiver. You can read more about green cards by clicking on family-based or employment-based immigration at www.myattorneyusa.com.